1. Field of the Invention
The present invention relates to an ink, an ink jet recording method which employs the same, and an apparatus or tool which employs the same. More particularly, the present invention relates to a high-speed fixing type ink capable of high definition and high image quality recording not only on sheets of coated paper specifically prepared for use in ink jet recording but also on sheets of non-coated paper, i.e., sheets of plain paper, generally used in offices or schools, such as copying paper, reporting paper, bond paper or payment slips; an ink jet recording method; a recording unit; an ink jet recording apparatus and an ink cartridge.
2. Description of the Related Art
Ink jet recording inks having various compositions have been reported. In recent years, research and development have been made on the composition and properties of the ink to provide an ink which fixes at a high speed to sheets of plain paper generally used in offices, such as copying paper, report paper, notebooks or letter paper, and which assures high definition recording on sheets of such paper.
For example, inks in which a high-boiling point organic solvent, such as glycol, is present for the purpose of preventing drying and clogging are known. Such an ink does not readily penetrate sheets of highly sized plain paper and hence does not dry fast when used in recording performed on such paper. Consequently, the ink may smear the hand when it is accidentally rubbed by the hand or the paper may be smeared by the ink.
Accordingly, it has been proposed in Japanese Patent Laid-Open No. 29546/1980 to add to the ink a large amount of surface active agent in order to promote penetration of the ink into the paper. However, the resultant ink runs greatly on some type of paper. Furthermore, when the ink jet head is charged with the ink, the ink may retract from the orifice surface and not be ejected. Conversely, the overall orifice surface may become wet with the ink and not eject the ink.
Japanese Patent Laid-Open No. 57862/1981 discloses a method of preparing a strong alkali ink. However, the strong alkali ink is hazardous, and may run and not dry fast on the sheets of paper which are subjected to sizing using some type of sizing agent, for example, sheets of neutral paper.
Japanese Patent Laid-Open No. 147870/1981 discloses a recording liquid in which alkyl ether of polyoxyethylene-polyoxypropylene block polymer is present. However, since block polymer behaves exactly in the same manner as the surface active agent, the resultant ink runs in an irregular whiskered fashion and hence deteriorates printing quality, although it penetrates the paper well.
Various other types of inks have also been proposed up to the present. However, no single ink is known which fulfills all the conditions regarding spreading, drying and clogging.